Weight regulator for rotary drills



Feb. 2l, 1928.

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A. P. BRASWELL WEIGHT REGULATOR FOR `ROTARY DRILLS Filed NOV. 16, 1923 Patented Feb. 21, 1928.

UNITED STATES i 1,660,033 PATENT OFFlCbl.

ALFRED P. BRASWELL, 0F BELLFLOWER, CALIFORNIA.

WEIGHT REGULATOR FOR ROTARY DRILLS.

` Applicationy led November 16, 1923.

This invention relates to means for insuri ing a constant and known degree ot pressure on an earth-boring bit, such as is used in drilling deep wells.

An object is to provide a simple, eiective, substantial and reliable means enabling the accurate determination of a degree of pressure to which a rotary deep well or other earth-boring bit may be subjected.

Another object is to provide a pressure form of joint section adapted to be readily introduced into a drill pipe string whereby when thedrill has been lowered to i'ull or bottom position, the drill will cometo rest and be subjected to the load ot any desired number of sections of drill pipe as determined according to the toi-mation to be met and which load will be constant at alltiines during the operation ot the lower drill, irrespective of the length or variation ot the drill pipe string above a predetermined number of sections which are utilized to transmit to the drill the desired load or pressure to effect cutting.

As is well-known, when a drill pipe string for driving a drill is lowered, itis diilicultto prevent an excess of pressure uponthe bit because ot the great weightwhich is the result of the great length ot' drill string. By my invention, irrespective oi the length ot the string, it is possible to have a constant and given weight effective on the drill in the hole.

Other objects and advantages will be made manifest in the following specication ot an embodiment of the invention illustrated in the accompanying drawings, wherein:

Fig. 1 is a. vertical section illustrating diagrammatically a drill string in a hole, with the present invention in place in the string.

Fig. 2 is a detailed longitudinal `section of the improved connector.

Fig. 3 is a cross-section on line 3-3 of Fig. 2.

The present invention consists ot a tubular body 2, which may be ot any desired length and of any desired diameter according to the size of the drill pipe with which it is to be combined. The lower end of the body is `provided with a tool joint pin 2a to thread into a tool joint 3 of standard or wellknown form, and below which may extend any number ot drill pipe sections Il, Fig. l, the lowermost of which may be provided with any type of rotary drill bit 5.

It is desirable that a constant and prede- SeriaI No. 675,111.

termined load be subjected to the drill bit so as to prevent the excess pressure from too rapidly breaking down the small teeth of the usual rotary cutters C in bits having rotary cutters. It is welldrnown that rotary bits having rotary cutters have to be repeatedly pulled troni the well-hole and sharp`- ened because of the wearing oit of the small sharp points of the teeth, or to enable re grinding of the edges oi disc cutters when such is the type. Because of the great cost of lowering in and pulling out a drill string of great length necessary for the purpose ot sharpening or replacing the cutters, it is desirable that these cutters be protected against the entire load ot the drill string. Therefore in my invention I connect any number ot drill pipesections `4 according to the weight to be imposed upon the bit cutn ters C. For instance, I may connect a. string of about l5 sections and utilize their weight to press the bit down, and this irrespective of the number of sections above `the selected lower l5 (or other number) sections.`

Therefore, I provide the body 2 and upon this mount a sliding sleeve 8, the lower .end of which is provided with hey-lugs 8a, sliding in key-ways or grooves 2b, cut or formed longitudinally in the body 2, so that while the shell 8 may slide up and downtelescopically on the body 2, the latter will be rotatively driven in the ordinary manner of rotary drill strings. The connector body 2 is attached at its upper end to a wash-down pipe 9, extending slidably through a tool joint `10 to the upper end of which is connected a contiguous drill pipe section at, any number ot which may be run to the head of the well.

The washdown pipe 9 is provided with a gland 9a in the joint lO.

The shell 8 is threaded on the pipe joint 10 in the usual manner at 10a.

From the above it will be seen that the drill string can be lowered into the well in the normal manner; the connector body 2 resting in suspended position on the keying lugs 8a of the shell 8, while the drill is being lowered. When the bit reaches land at the bottom of the well the drill string and shell above the connector body 2 is permitted to slide down a suitable distance, as is clearly shown in Fig. 2, with the result that the weight of the string above the connector body 2 is entirely removed trom the drill and is carried by the brake system at the itl head of the Well. There-'oe, While the upper portion of the drill string is rotated in the usuel manner, this will result in the rotation of the bit 5 while this is subjected only to the load or the parts extending from the drill connector 2 down to tbe bit, end therefore insure a const-ent and normal pressure on the bit. The desired downward movement ot the bit during cutting is readily permitted by the slidinzgof thel body 2 down in the shell 8 during rotation; the suspended portion et the drill string being` intermittently lowered as'drilling procee si Suitable und appropriately arranged ports may be provided to providev for the escupe oi Water Which may be trapped Within the shell. Such ports are indicated at 1l.

Further embodiments, modilicetions and variations may bel resorted. to within the spirit of the invention.

What isclaimed is;

l. r Weight regulator tor rotary drills comprising in combinetion with e stringi" et drill-pipe, a connector composed oj' e hollon7 member adapted to be secured :it one end to a section of the stringn seid member provided et the opposite end with en internal shoulder', a second member adapted' to be secured to another section ot the stri-ne' and' elidebly keyed eigninst rotation to the tirst mentioned member, seid second member being` provided with external shoulder engagenb'le with seid' internal slioul'der, there being pessagesextendling thi-onwil one ot seid shoulders., whereby e predetermined Weight may be applied to a bit in the drill:- ing operation, seid' predetermined Weight being determined by the mass oft the dr pipe beneath seid connector 2. A Weight i-egulator for rotary drille comprisingl in combination with a c ring; ot drill-pipe, a connector composed ot n hollow member adapted to be secured et one end to a section of the string, seid member beingl provided et the opposite end with :in iuternal shoulder, e second member adapted to be. secured to another section oi? the string and slideble keyed against rotation to the first mentioned member, seid second member being` provided with an external shoulder enge'geable with said internal shoulder., there being passages extending throvoh seid ei;- ternel shoulder, whereby :i pri i i Weight muy be applied toy :i bit in ine drilling operation, said predctormined Weight being deter nined by the muss ot the drill-- pipe beneath seid connector.

3. A Weight regulator t'or rotary drills comprising in combinntiou with :i stringi` ot drill-pipe, n connector composed ot :i hollow member adapted to be secured :it one oud to n section et the strifne seid member being; provided :it the opposite end with an internnl shoulder, a .second membfr :idnoied to be secured to :mother section or the string* and slidably keyed against rotation to the first mentioned memben seid second member being provided. with sin external, .shoulder engageable With seid internal' shoulder, there being passages extending through seid external shoulder on said second; member whereby a predetermined weinlit determined by the Weight of seid second ,rinfi ol drillpipe may be aippliedi tothe bit at all times during the drilling operation.

ln testimony whereof l have signed my neme to this specification.

ALFRED P. BRASYVELL.

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